The composite materials which are composed mainly of preforms with a fibrous structure and a matrix generally consisting of a plastic material (thermoplastic or thermosetting resins) ensure the cohesion of the structure, and are being used increasingly frequently in many industries and in particular in the aeronautical and space industries.
The manufacture of the composite material parts requires firstly production of profiled preforms with a cross-section and/or shapes which are more or less complex, using elementary preforms which are cut out then formed and/or assembled mechanically for the purpose of obtaining the required profile.
Profiles of this type are then frequently firmly attached to skins with a fibrous structure, such as to produce panels made of composite materials comprising structural reinforcement elements.
Usually, the different profiles and the skin are then compacted before being installed in a molding tool, in which they are then assembled by coating by means of a matrix.
However, these assemblies are not suitable for withstanding consequent wrenching forces, such that wrenching forces of this type make it necessary to reinforce the assemblies by means of additional assembly units, conventionally consisting of mechanical assembly units of the rivet type.
Consequently, the production of composite panels which can withstand wrenching forces requires a plurality of successive steps (compacting, molding, mechanical assembly, etc.).
A process for production of complex steel sheet parts made of composite material is known for example from patent document FR 2 717 735. The molding tool comprises a matrix of flexible boxes previously compressed onto a skin of pre-impregnated fabric with a three-dimensional mesh. This mesh comprises bracing strips which are interposed as stiffeners between the boxes. However, this tool does not make it possible to coat flexible preforms which have not been previously compacted.
In addition, patent document EP 1 000 725 describes a mold matrix, the stainless steel materials of which have different thermal expansion coefficients in order to define inner cavities, so as to pre-compress the body to be molded.
The object of the present invention is to eliminate these disadvantages, and its main objective is to provide a molding tool which makes it possible to coat flexible preforms which have not been previously compacted, using a matrix.